Promising New Results from Fragile X Drug Trial

At the International Fragile X conference held in Michigan last week, researchers working in partnership with Seaside Therapeutics presented promising results from a Phase II clinical trial with compound STX209. The research was presented by Elizabeth Berry-Kravis, MD, PhD, (Rush University Medical Center in Chicago, Illinois) and Randi Hagerman, MD, (M.I.N.D. Institute).

The study followed 63 patients with Fragile X from three groups spanning 6 to 40 years of age. The aim of the study was to investigate the safety and efficacy of STX209 across a broad range of individuals with Fragile X. The research team specifically looked at behavioral and cognitive measures that might indicate benefit from the drug. Indeed, they found statistically significant improvements in sociability in a pediatric group who had scored low on scales of sociability prior to the treatment. This result is particularly important because impairments in social function are a core feature of Fragile X, and also a core feature of autism spectrum disorders (ASD).

In a press release from Seaside Therapeutics, Dr. Hagerman offered a perspective on the results her team has observed. “A majority of the patients enrolled in the STX209 study are participating in the ongoing open-label extension study and are continuing to benefit from treatment with STX209,” said Dr. Hagerman. “Physicians and parents are reporting increased sociability and communication and decreased outbursts and tantrums. In several cases, patients have been successfully withdrawn from other medications, including mood stabilizers, anti-depressants and, most importantly, anti-psychotics—a significant benefit for patients given the severe side effects associated with this particular class of drug. It is my hope that, with further study, STX209 may be able to play a much needed role in improving the symptoms of fragile X syndrome and help patients and their families achieve an improved quality of life.”

These results are exciting for individuals and the families of those living with Fragile X. However, perhaps the greater excitement lies in what may come next. Fragile X is the most frequently observed genetic syndrome in individuals with ASD. Synaptic over-excitability has been observed in animal models of autism and is believed to be a common neurobiological underpinning. Seaside Therapeutics is currently exploring the potential for benefit in individuals with ASD through a clinical trial of STX209 in adults, adolescents and children with ASD. We anxiously wait for further data on the use of this compound.